We're back, & Overs action design

Overs Pianos sec@overspianos.com.au
Sat, 28 Jul 2001 09:51:51 +1000


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David, Dale and all,

My apologies for the delay in responding to this post. Just arrived 
back in Sydney from LA on Thursday. Our piano was uncrated for a 
private showing in LA, and is now on its way back to Sydney (the 
Australians haven't seen it yet). For those who are wondering, our 
225 piano will be selling from piano No. 004 for US$49,000, plus 
transport costs and any applicable taxes and duties (Nos. 004 and 
005, both 225 cm pianos as is 003 - are presently under construction 
and available). No. 003 will remain with us as a promotion and hire 
piano. Further information will be published on our website soon 
(perhaps within four weeks).

I was a great pleasure to meet so many of you in Reno. Overall the 
convention was an overwhelming event for us. However we thoroughly 
enjoyed the occasion. Our thanks go to so many of you for your 
positive comments and enthusiasm for our piano and the new action. 
There has been considerable manufacturer interest in using our action 
under licence and I look forward to our future as a grand piano 
manufacturer. There is so much performance improvement in the modern 
piano yet to be discovered.

At Reno, I was impressed with the MBA system on the Fazioli 278, and 
also the exhibition pianos from Bl=FCthner, Seiler and Sauter. Bl=FCthner 
appear to be one of the few manufacturers incorporating a modern 
approach to scaling, with a B27 first note on the long bridge of a 
7'8" piano - congratulations Bl=FCthner. The Seiler was a very 
impressive instrument for a mid priced piano. It was encouraging to 
see that a few manufacturers remain committed to building quality 
into their product, as opposed to some others who spruke endlessly 
about quality which is sadly lacking.

>. . .  I have some questions about your action design.  I have 
>copied the pianotech list as I am sure that those who did not have 
>the opportunity to see it will be interested.  I could not attend 
>your class in Reno due to some conflicts so forgive me if you 
>covered this material there.

No problem, there were so many excellent classes. Yes I did cover the materi=
al.

>  1.  I assume that the layout is designed to put all the friction 
>points on the convergence lines.

Indeed it is.

>  The most noticeable change therein is the capstan which angles 
>toward the front of the key rather than the back.

But the most noticeable performance improvement comes about from the 
placement of the jack/knuckle contact, at a mean position which is on 
the line of centers.

>  Is the angle of the capstan set at the tangent to the arc scribed 
>by the movement of the key at that point

Yes.

>   Is the idea that with the wippen heel set at 90 degrees to the 
>capstan that there is no sliding and thus reduced friction?

It is slightly more efficient than the conventional setup and the 
friction is reduced.

>  It seems that this would also result in greater wippen speed since 
>there is no lateral movement allowing you to use a slightly longer 
>knuckle radius.

The wippen speed is basically a function of the resultant ratio 
between the key and the wippen, which will be set according to the 
division of the length from the balance pin hole to the wippen flange 
center distance. In the case of our action, the wippen is rotating 
about 7% faster than normal, but the hammer speed will be determined 
by the overall hammer/key ratio (as it will for all other actions).

>  2.  What is the product of all the distance leverages and does it 
>correlate to a specific key dip/blow distance combination?  Have you 
>found generally that there is a specific and absolute 
>correlation between total distance leverages?  For example, TSDL =3D 
>6.5 correlates to 10mm dip and 45 mm blow, and for any deviation of 
>x a corresponding change in dip and blow of y must be made.

This was all covered in the class. I won't try to cover it now but I 
will, perhaps in a future class. It is so much easier to deliver 
content at a white board verbally.

This action is designed to operate with a key dip of 9.8 to 10.25 mm 
max. with a 45 mm blow distance. The overall hammer/key ratio was set 
at 6.0:1 on the Reno exhibition piano. We will decrease this at 
little when the piano arrives back. With our action, since the wippen 
heel cloth is aligned on the line of centers at half key dip, the 
capstan can be relocated to reset the hammer/key ratio, while the 
capstan/heel contact will remain on the line of centers. I'll keep 
you posted on developments.

>  3.  What is the friction range in the action that you had in Reno.

It was surprisingly high at around 12 grams, when compared to figures 
typical for this action (I discovered why this was so when the piano 
arrived in LA). With a down-weight of 50 grams, the up-weight was 
just a little higher than 25 grams when tested in Reno (our action 
model, and No. 003 before it left Sydney, had an up-weight in excess 
of 35 grams). Typically, our action performs with a friction of 
between 5 and 7 grams. When preparing the piano in LA for viewing, I 
discovered that the once-highly-polished capstans had tarnished 
significantly during the flight from Sydney to the US, and the 
jack/roller surfaces were anything but smooth. When we uncrated the 
piano in Reno I noticed that the strings and fittings appeared to 
have been wet since leaving the workshop. The capstan condition made 
me realise that condensation in the aircraft during transit was the 
problem. After smoothing the jacks again, skimming over the rollers 
(and lubricating them with Bill Spurlock's amazing teflon powder) and 
polishing the capstans, the performance of the action returned to 
where it should have been. At least the action performed quite well 
in Reno considering the poor state of the friction surfaces. I didn't 
think it necessary to check the surfaces in Reno, since the piano was 
only assembled about two weeks before the convention, when all 
surfaces were checked prior to assembly.

>  4.  Your shank uses a 20mm knuckle to center pin radius.  Was this 
>done primarily to reduce friction at the knuckle because of your 
>intention to use such a heavy hammer? 

No, the 20 mm knuckle distance, the revised wippen length of 75 mm 
(jack center to wippen center distance) and the reduced knuckle 
diameter of 9 mm combine to place the knuckle/jack contact on the 
line of centers at mid key-stroke (this is part of our patent claim). 
It's the combination of the three parameters together which achieves 
the geometry change.

>  5.  Just for fun.  All things being equal, what happens if you 
>reorient a Steinway capstan toward the keyboard by 8-10 degrees, put 
>it on the line of convergence and spin a slanted heel around 
>backwards to put the two in line?

It would slightly improve the geometry, but it would also be an 
infringement of our patent claim if the alteration were to be sold to 
an end user.

>  It was a pleasure meeting you.  It's a beautiful piano you've 
>produced and I wish you the best of luck with your project.

Thank you David, and thank you to the many others who have sent such 
positive emails. I feel honored to be the recipient of so much. 
However, 'The standard', to use a phrase, is yet to be set.

I will publish my class handout on our website shortly. I'll let the 
list know when it up.

Regards,

Ron Overs
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Website:  http://www.overspianos.com.au
Email:        mailto:ron@overspianos.com.au
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